Publications

The Whakamaru group ignimbrites are widespread voluminous welded ignimbrites which crop out along the eastern and western margins of the Taupo Volcanic Zone (TVZ), New Zealand. The ignimbrites have a combined volume exceeding 1000 km3, and were erupted from a large caldera in the central TVZ around 340 ka, following a c. 350 ka hiatus in caldera-forming activity in TVZ. Analysis of...

Replicable, pronounced orientation of discoid pebbles (≥8 mm) embedded on surfaces of large (∼10 m3) experimental debris-flow deposits reveals that strongly aligned, imbricate fabric can develop rapidly over short distances in mass flows. Pebble long axes aligned subparallel to deposit margins as well as subparallel to margins of surge waves arrested within the deposits. Pebble alignment...

A new method of delineating lahar hazard zones in valleys that head on volcano flanks provides a rapid, objective, reproducible alternative to traditional methods. The rationale for the method derives from scaling analyses of generic lahar paths and statistical analyses of 27 lahar paths documented at nine volcanoes. Together these analyses yield semiempirical equations that predict...

Travel times for wet volcanic mass flows (debris avalanches and lahars) can be forecast as a function of distance from source when the approximate flow rate (peak discharge near the source) can be estimated beforehand. The near-source flow rate is primarily a function of initial flow volume, which should be possible to estimate to an order of magnitude on the basis of geologic...

River sedimentation caused by the May 18, 1980, eruption of Mount St. Helens, Washington, has been monitored in a continuing program by the U.S. Geological Survey. In this report, sediment discharge and changes in sediment transport are summarized from data collected at stream-gaging stations near Mount St. Helens during the years 1980 through 1990. The objectives of the monitoring...

Debris flows are rapidly flowing mixtures of rock debris, mud, and water that originate on steep slopes. During and following volcanic eruptions, debris flows are among the most destructive and persistent hazards. Debris flows threaten lives and property not only on volcanoes but far downstream in valleys that drain volcanoes where they arrive suddenly and inundate entire valley bottoms...

Sulfur dioxide (SO2) emission rates from Kilauea Volcano were first measured by Stoiber and Malone (1975) and have been measured on a regular basis since 1979 (Casadevall and others, 1987; Greenland and others, 1985; Elias and others, 1993; Elias and Sutton, 1996). The purpose of this report is to present a compilation of Kilauea SO2 emission rate data from 1979 through 1997 with...

Mount Rainier is an active volcano reaching more than 2.7 miles (14,410 feet) above sea level. Its majestic edifice looms over expanding suburbs in the valleys that lead to nearby Puget Sound. USGS research over the last several decades indicates that Mount Rainier has been the source of many volcanic mudflows (lahars) that buried areas now densely populated. Now the USGS is working...

No abstract available.

Cerro Campanario, a towering landmark on the continental divide near Paso Pehuenche, is a glacially eroded remnant of a mafic stratovolcano that is much younger than previously supposed. Consisting of fairly uniform basaltic andesite, rich in olivine and plagioclase, the 10-15 km3 edifice grew rapidly near the end of the middle Pleistocene, about 150-160 ka, as indicated by 40Ar/39Ar and...

No abstract available.

No abstract available.